Occasional interference experienced in the channels of communications satellites has prompted an analysis to see how radio frequency interference (RFI) might be detected from space. RFI may be experienced on any type of satellite, including commercial and scientific satellites. For a satellite in geostationary orbit that interference may come from anywhere in the hemisphere under the satellite. Because the location of an interfering transmitter is so uncertain, traditional means for geolocating it is not effective. “Down-looking” detectors are needed to detect the “up-looking” interference. Moreover, a low cost, simple solution to the problem – one in which the cost to geolocate is small relative to the cost of the downtime in the channel – is required in order to make the solution tractable.